Ladders are commonly used for a variety of applications and are of two general types. One type is a folding ladder, commonly called a step ladder, which is self supporting. Step ladders are typically used for such tasks as pruning, painting ceilings, or other similar tasks where it may be impossible to lean the ladder against a structure for support. The other type of ladder which is well known is the straight extension ladder. This type of ladder is simply leaned against the wall or some other structure and stood or climbed upon.
Ladders which are constructed so that they may be used as both step ladders and as straight extension ladders have long been known in the art. Typically, such ladders are constructed with hinges in the middle of the side rails. The hinges permit the ladder to be folded into a step ladder configuration or unfolded into a straight extension ladder configuration. Such ladders, commonly referred to as combination step and extension ladders, are very versatile and they combine the desirable features of both types of ladders.
Further improvements on such step ladders include foldable ladders or ladders which are adjustable to a variety of positions so that they can be used as scaffolding or for other support configurations. Such foldable or adjustable ladders include two or more adjustable locking hinges which enable the ladder to conform to the desired positions.
Hand trucks are also known in the art and are commonly used for transporting a variety of goods. Typical hand trucks comprise a pair of spaced apart wheels, each wheel rotatably attached to one end of a side rail. An opposite end of each side rail terminates in a handle means which an operator grasps in order to direct and control the hand truck. A support platform is provided extending forward of the wheels, attached to the side rails and perpendicular to the side rails. The support platform is provided to hold whatever goods are to be transported. Bracing means such as cross members or the like are attached to and extend between the side rails. Such bracing means serve to structurally reinforce the hand truck and provide support to hold the goods to be transported.
The wheels of known hand trucks are generally positioned with respect to the support platform and side rails such that when the hand truck is in a vertically upright position, the support platform rests on the floor and the wheels are positioned slightly above the floor. Inadvertent rolling is thus prevented by preventing wheel contact with the floor during storage in a vertically upright position. Slightly tilting the hand truck rearward will cause the wheels to contact the floor and the support platform to move away from the floor, thus enabling rolling of the hand truck.
Hand trucks and ladders, particularly step ladders, are becoming increasingly common in households. Although most households indeed have some type of step ladder, such ladder is generally used infrequent enough so as to warrant its storage in some type of storage place.
Unfortunately, lack of adequate storage space has become of increasing concern in view of the increased number of city dwellers, lack of adequate housing, large number of condominiums and cooperative apartments and the general need to stabilize the cost of new construction.
Such a lack of adequate storage space has contributed to the above mentioned improvements in foldable ladders, i.e. ladders which are sectionally collapsible so as to be easily stored.
In addition to the lack of adequate storage space, a need for ease of transportability has led to the concept of foldable ladders. Clearly, men, women and children may more easily transport a short folded ladder rather than a long non-folded ladder.
Unfortunately, the advantage of foldability is often accompanied by the disadvantage of additional weight. Such additional weight generally arises due to the requirement of additional materials to insure structural stability and sturdiness of the hinge means.
Thus, a combination foldable ladder and hand truck is desirable, having the advantages of relative lightweight, transportability, structural stability, collapsability and use both as a ladder and a hand truck.